Soldering Stainless steel

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I just wanted to share my soldering experience. After reading this thread I decided I would give it a shot. I used silver plumbing solder and liquid flux I picked up from the hardware store (Menards), so nothing fancy. I sanded the inside and outside of the keg and cleaned all pieces with acetone. Now I have soldered less than 4 times my entire life and using my Benzomatic propane torch I was able to solder in a 1/2 inch brass coupling with no leaks. I then picked up my keggle by the connection and swung it around my shed, it is not going anywhere. I want to thank all who posted advice. To anyone who wants to try this I cannot vouch for long term but my first observations would indicate an extremely strong bond.
 
Great thread - I have learned more about soldering from it than I ever expected. I would be honored to join the group of "less than intelligent" questions and ask how you guys clean your soldered/braised/etc joints so well?
Thanks!
 
Great thread - I have learned more about soldering from it than I ever expected. I would be honored to join the group of "less than intelligent" questions and ask how you guys clean your soldered/braised/etc joints so well?
Thanks!
Re: the solder joints - I do cleanup once the solder solidifies and before it has a chance to cool off. This way the flux does not have a chance to stain the metal. A little more flux (liquid) on a slightly damp cloth works wonders.
 
If you added a fitting or coupling after making a dimple like GreenMonti does on his Tig welded fittings but still had the tight forced fit with the pocket facing outside (dimpled inwards) then you could solder fill that depression flush with the kegs outside surface. Just make sure your good and clean before soldering first.
This added dimple area filled with solder will greatly increase the fittings joint strength beides being pressed into the keg on the inside holding the inside around the fitting or coupling. Soft or silver solder this pocket flush with the kegs surface.
 
Here is my soldered Keggle has a sight glass thermo port recirc port on top and outlet!!

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Quick questions. With solders like staybrite-8 there is a relatively low melting point ~400F. Is this something to worry about if you use a propane burner on your BK/keggle? Do I need to worry about fittings coming off or the solder melting from the burner? Anyone have first hand experience?
 
As long as the BK is out of the way of direct flame it should be just fine, and with the liquid/wort in there it really can't get much hotter than 212 anyway.
 
I just bought the whole 9 yards of equipment for 3 keggles from bargainfittings, and now i see this thread, soldering is starting to look real good and i'm considering repurposing the entire stock of gear i got from bargainfittings into soldered joints, as i've only done up one kettle so far weldless.

Question: can i solder the outward threaded nipples onto the keg, basically in the same configuration as weldless, with solder replacing the o-rings as the seal or would it be better to solder the inward threaded couplers/bulkheads as the part that goes through the keg? though that would require a larger hole being drilled

if i decide to solder it i'll do it this weekend, will take pics
 
I picked up some Oatey liquid flux from Menards and it made all the difference in the world. Its cheap too ($3.99 for 8oz.
 
I have some 56% silver solder from Harris that I am going to use. I also have some of the Harris Stay-Silv White Flux. Will this be fine, or should I go with a different (liquid) flux to make it easy on myself?
 
I tried white stay silv and stay clean paste and neither worked for me. It beaded up like water on a waxed car. However the liquid flowed nicely. I would get some liquid if I were you.
 
I have some 56% silver solder from Harris that I am going to use. I also have some of the Harris Stay-Silv White Flux. Will this be fine, or should I go with a different (liquid) flux to make it easy on myself?
The Harris 56% Silver is for brazing. (Solid @ 1145°F & Liquid @ 1205°F) It is a lot different than soldering with Stay-Brite #8 (Temp 430°F - 535°F)
 
This may be a stupid question, then, but will a good propane torch give me what I need to do the brazing with the 56% silver, or do I need to break out the oxy-acetylene torch? I am just doing small fittings on thin walled vessels.

Would it be worth me just going and getting the Stay-Brite #8 and returning the other?
 
The Harris 56% Silver is for brazing. (Solid @ 1145°F & Liquid @ 1205°F) It is a lot different than soldering with Stay-Brite #8 (Temp 430°F - 535°F)

Yeah you're right I wasn't paying attention. If you plan to use Safety-Silv 56 then you need to use Stay-silv according to Harris. If you're using Staybrite 8 or plumbing solder then use liquid flux.
 
This may be a stupid question, then, but will a good propane torch give me what I need to do the brazing with the 56% silver, or do I need to break out the oxy-acetylene torch? I am just doing small fittings on thin walled vessels.

Would it be worth me just going and getting the Stay-Brite #8 and returning the other?

I believe propane will not be hot enough to braze the 56% silver. I would get the #8 for ease of use, unless you have experience brazing.
 
I believe propane will not be hot enough to braze the 56% silver. I would get the #8 for ease of use, unless you have experience brazing.
I believe that is very accurate. You might stand a chance with MAP, depending on the torch and the overall mass of the fitting. I know that I have a rough time unless I'm using acetylene with Safety-Silv 56. Another thought if you do use Safety-Silv 56, you ought to use Stay-Silv Black Brazing Flux instead of Stay-Silv White as it is less prone to burning under long exposure to the heat you will require. It is also easier on Stainless Steel.

My choice? Stay Brite #8 & Stay-Clean Liquid flux.
 
I appreciate the feedback and will switch out what I have. Thanks.

Could I use the Stay-Brite #8 to solder copper to the kettle without issues?

Where are people able to find this locally? or is everyone ordering it?
 
Yes you can use Stay-brite 8 on copper. I found it at my local Airgas. They carry a full line of Harris products but were out of Stay-clean liquid the day I was there.
 
I believe propane will not be hot enough to braze the 56% silver. I would get the #8 for ease of use, unless you have experience brazing.

I can silver solder, real silver solder not any cross mix of a low temp silver with my torch designed to run off natural gas and 60 psi compressed air not pure O2. I've welded mid 1600's 10" plus diameter by 3/16" thick cracked clock bells before instead of using O & A. Buildup then dress plus add the casted finish then an acid bath the welded crack repairs hard to even locate. The ring is back vs a thud sound. One must be rather quick with a soft O & A flame preventing overheating.
 
I can silver solder, real silver solder not any cross mix of a low temp silver with my torch designed to run off natural gas and 60 psi compressed air not pure O2. I've welded mid 1600's 10" plus diameter by 3/16" thick cracked clock bells before instead of using O & A. Buildup then dress plus add the casted finish then an acid bath the welded crack repairs hard to even locate. The ring is back vs a thud sound. One must be rather quick with a soft O & A flame preventing overheating.
That is awesome and I applaud your skills.

On the other hand, A lot of us have never even soldered a copper plumbing line together let alone Silver "soldering" stainless steel. Also, considering pure Silver has a melt temp of 1761ºF, it is really tough to do for the norm of day to day metal bonding.

Just saying...
 
I just thank everyone on this thread for throwing this idea out there. It worked great. I built the tool listed on and earlier page and pulled a tapered coupler through some 7/8" holes and installed 5 couplers to my HLT. It went very smooth. I used standard lead free plumbing solder with Stay-Brite liquid flux.

Last night I also was able to solder a 1" stainless steel nut onto my kettle that that I can just thread my electric heating element directly into the kettle. I simply drilled a hole and lined up the nut so that the holes were aligned. I then used the tool I made to pull the couplers through as a clamp and pinched the flat nut onto the cleaned and sanded kettle. I then used quite a bit of solder and it's rock solid. Beats heck out of weldless in my opinion.
 

P-J:

what would this fitting be called, and where would I be able to buy one? It looks like it would be perfect. A nice big stable shoulder, and a smooth mating surface.


Alternatively, could somebody post a picture of what fittings besides a coupling people have had success with? Are you guys basically just using weldless kits without the o-rings?
 
I talked with a friend yesterday about soldering SS. He was having difficulties soldering a fitting to an aluminum kettle. He will try again this morning.

One of the things he mentioned was this forum as he participates here. He mentioned this thread so I took a look this morning and decided to join and post a comment.

I've been using StayBrite-8 solder and StayClean liquid flux for years. I think it is a great solution for us brewers in fabricating equipment.



This is just one example of the possibilities (click the pix for the inside view)

Another is a fitting on a hopback that I fabricated:



The image is the dry fit - click it to see the finished joint.

One of the things I like about StayBrite-8 is that it has a plastic range that allows me to easily fill gaps.

Anyway, I figured I'd show off a little.

Thanks.

A tight with stepped fitting will geatly increase that soldered joints strength, slightly sticking inside the keggle then use a flap wheel to blend what is sticking inside as the end of the fitting does not match the kegs internal radius. When dressed flush it'll look as a one piece unit inside your keg.
There goes the Tig welders business from home brewers now not needing their kegs Tig welded.
 
P-J:

what would this fitting be called, and where would I be able to buy one? It looks like it would be perfect. A nice big stable shoulder, and a smooth mating surface.


Alternatively, could somebody post a picture of what fittings besides a coupling people have had success with? Are you guys basically just using weldless kits without the o-rings?
It is a fitting I found a bunch of years ago. It was a standard 1/2" SS coupling that I had a machine shop turn down for the kettle hole and interior. I've not seen that fitting since.

If you do not mind using brass, mcmaster.com has one that would work very well with solder as is. (click the link)

Hope this helps.
 
Absolutely, I'm using them for my keggles. I also have the jam nut, so the solder joint will be reinforced with the nut on the inside.
 
Absolutely, I'm using them for my keggles. I also have the jam nut, so the solder joint will be reinforced with the nut on the inside.

Ok, nice strong joint then! The solder is really just shiny pipe dope at that point...no question of strength of the fitting at all when backnutted like that.:mug:
 
Would a bushing like this work soldered in a kettle....just an idea?
Keep in mind that this fitting:
1-2x3-4-bushing.jpg

will act like a 1/2 coupling. You can only thread a 1/2" pipe into it from the hex nut side. That being said, how will you use it and have a pickup tube inside your kettle?

I suppose you could use a 3/4 X 1/2 reducer inside.
 
Keep in mind that this fitting:
1-2x3-4-bushing.jpg

will act like a 1/2 coupling. You can only thread a 1/2" pipe into it from the hex nut side. That being said, how will you use it and have a pickup tube inside your kettle?

I suppose you could use a 3/4 X 1/2 reducer inside.

Hmmm some must be different mine is threaded all the way through. I'll post a pic in a bit.
 
Hmmm some must be different mine is threaded all the way through. I'll post a pic in a bit.
I have no doubt that it is threaded completely through. I think the issue really is that it is a tapered plumbing thread that is cut from the hex side only. I imagine that one would have to be really lucky to find a part that would thread into the small thread diameter side. Or - run a pipe tap part way through from that side?
 
Here is mine with the jam nut on it and nipples threaded into each side. I tried to show how its threaded from each end.
4445880164_7c94f68151_o.jpg

4445106043_f92bf690a1_o.jpg
 
P-J:

what would this fitting be called, and where would I be able to buy one? It looks like it would be perfect. A nice big stable shoulder, and a smooth mating surface.


Alternatively, could somebody post a picture of what fittings besides a coupling people have had success with? Are you guys basically just using weldless kits without the o-rings?

I just saw your post and I believe those are what I use. They are a bit pricey, but they work and look great. If you ever need to run up to 5200psi they are there for you :D

http://www.mcmaster.com/#48805k48/=6acdqb
 
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